The present invention relates to a connecting unit of a stand for percussion musical instruments, and more particularly relates to improvements in mode of connection between cooperating supporting elements of a stand used for holding percussion musical instruments such as snare drums and cymbals.
In one conventional connecting system used for such applications, a connecting unit includes a crown shaped connecting element which is fixed to one end of a supporting element and provided on one axial end with peripheral serrations. When two supporting elements are to be joined together at a selected cross angle, serrations on connecting elements of respective supporting elements are combined together in an angular relationship corresponding to the selected cross angle. The combination is then fastened by cooperation of a screw and a nut attached to the combination.
In another conventional connecting system used for similar applications, one end of a tubular supporting element (first supporting element) is provided with a sectral section which has a sectral opening in its central area. A pair of connecting elements (first connecting elements) are idly connected at their one ends to the proximal area of the sectral section of the tubular supporting element via proper spacers. Another cylindrical supporting element (second supporting element) is connected at one end to the proximal end of a U-shaped connecting element (second connecting element). When the two supporting elements are to be joined together at a selected cross angle, the sectral section of the first supporting element is sandwiched by two branched of the second connecting element in an angular relationship corresponding to the selected cross angle. A joint between the first supporting element and the first connecting elements are the screw fastened. Concurrently, a joint between the second supporting element and the second connecting element in also screw fastened.
In a further conventional connecting system used for like applications, a tubular supporting element (first supporting element) is provided at one end with a frustconical connecting element (first connecting element) having a center projection. Another supporting element (second supporting element) is provided at one end with a disc shaped connecting element (second connecting element) having a conical center hollow. When the two connecting elements are to be joined together at a selected cross angle, a conical rubber piece is attached over the center projection of the first connecting element and the second connecting element is put into combination with the first connecting element via the rubber piece in an angular relationship corresponding to the selected cross angle. Finally, the combination is screw fastened.
In the case of the first conventional example, the degree of cross between the two supporting elements is limited by the serration pitch on the connecting element. That is, this conventional system is very poor in freedom of selection of the cross angle. No continuous change in cross angle is permitted.
The second conventional example appears to allow continuous change in cross angle between the two supporting elements. In practice, however, the degree of cross angle is limited by the shape of the sectoral section of the first supporting element. In addition, the screw fastening the joints is rather unstable and much vurnerable to vibrations. Stated otherwise, the original cross angle is liable to be lost during long use.
Fastening in the third conventional example is totally dependant upon rubber friction only, which cannot assure reliable combination for a long period. Not only frequent vibrations but also rubber aging seriously degrades fastening power.